@matheusbsbs / matheus-bagliano / commits / e394a16023

interpolate_path(): allow specifying paths relative to the runtime prefix

Ever since Git learned to detect its install location at runtime, there was the slightly awkward problem that it was impossible to specify paths relative to said location. For example, if a version of Git was shipped with custom SSL certificates to use, there was no portable way to specify `http.sslCAInfo`. In Git for Windows, the problem was "solved" for years by interpreting paths starting with a slash as relative to the runtime prefix. However, this is not correct: such paths _are_ legal on Windows, and they are interpreted as absolute paths in the same drive as the current directory. After a lengthy discussion, and an even lengthier time to mull over the problem and its best solution, and then more discussions, we eventually decided to introduce support for the magic sequence `%(prefix)/`. If a path starts with this, the remainder is interpreted as relative to the detected (runtime) prefix. If built without runtime prefix support, Git will simply interpolate the compiled-in prefix. If a user _wants_ to specify a path starting with the magic sequence, they can prefix the magic sequence with `./` and voilà, the path won't be expanded. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Jul 24, 2021 at 22:06 UTC e394a16023cbb62784e380f70ad8a833fb960d68

3 files changed +25

Documentation/config.txt

@@ -298,6 +298,15 @@ pathname::

298 tilde expansion happens to such a string: `~/`

299 is expanded to the value of `$HOME`, and `~user/` to the

300 specified user's home directory.

301 ++

302 +If a path starts with `%(prefix)/`, the remainder is interpreted as a

303 +path relative to Git's "runtime prefix", i.e. relative to the location

304 +where Git itself was installed. For example, `%(prefix)/bin/` refers to

305 +the directory in which the Git executable itself lives. If Git was

306 +compiled without runtime prefix support, the compiled-in prefix will be

307 +subsituted instead. In the unlikely event that a literal path needs to

308 +be specified that should _not_ be expanded, it needs to be prefixed by

309 +`./`, like so: `./%(prefix)/bin`.

310

311

312 Variables

path.c

@@ -12,6 +12,7 @@

12 #include "packfile.h"

13 #include "object-store.h"

14 #include "lockfile.h"

15 +#include "exec-cmd.h"

17 static int get_st_mode_bits(const char *path, int *mode)

18 {

@@ -723,6 +724,9 @@ static struct passwd *getpw_str(const char *username, size_t len)

724 * failure or if path is NULL.

725 *

726 * If real_home is true, strbuf_realpath($HOME) is used in the `~/` expansion.

727 + *

728 + * If the path starts with `%(prefix)/`, the remainder is interpreted as

729 + * relative to where Git is installed, and expanded to the absolute path.

730 */

731 char *interpolate_path(const char *path, int real_home)

732 {

@@ -731,6 +735,10 @@ char *interpolate_path(const char *path, int real_home)

735

736 if (path == NULL)

737 goto return_null;

738 +

739 + if (skip_prefix(path, "%(prefix)/", &path))

740 + return system_path(path);

741 +

742 if (path[0] == '~') {

743 const char *first_slash = strchrnul(path, '/');

744 const char *username = path + 1;

t/t0060-path-utils.sh

@@ -540,6 +540,14 @@ test_expect_success RUNTIME_PREFIX,CAN_EXEC_IN_PWD 'RUNTIME_PREFIX works' '

540 cp "$GIT_EXEC_PATH"/git$X pretend/bin/ &&

541 GIT_EXEC_PATH= ./pretend/bin/git here >actual &&

542 echo HERE >expect &&

543 + test_cmp expect actual'

544 +

545 +test_expect_success RUNTIME_PREFIX,CAN_EXEC_IN_PWD '%(prefix)/ works' '

546 + mkdir -p pretend/bin &&

547 + cp "$GIT_EXEC_PATH"/git$X pretend/bin/ &&

548 + git config yes.path "%(prefix)/yes" &&

549 + GIT_EXEC_PATH= ./pretend/bin/git config --path yes.path >actual &&

550 + echo "$(pwd)/pretend/yes" >expect &&

551 test_cmp expect actual

552 '

553